New Orleans – November 16, 2006 – Shire plc (LSE: SHP, NASDAQ: SHPGY, TSX: SHQ) announced the results of a study which suggested that stimulant medications such as ADDERALL XR® (mixed salts of a single-entity amphetamine product) are significantly more effective than non-stimulant medications in the treatment of patients aged 8 to 15 with Attention-Deficit/Hyperactivity Disorder (ADHD).

The study, a meta-analysis of 29 double-blind, placebo-controlled treatment studies undertaken over the past 25 years and involving nearly 4,500 children with ADHD, was presented today at the U.S. Psychiatric & Mental Health Congress in New Orleans.

"The results of the meta-analysis, along with their own clinical experience, may help physicians draw conclusions about an ADHD medication's relative effectiveness in the absence of direct head-to-head comparisons among leading prescription ADHD medications," said Stephen V. Faraone, Ph.D., lead researcher and director of child and adolescent psychiatry at State University of New York Upstate Medical University. "By studying the magnitude of different drug effects on ADHD in children, my colleagues and I found that stimulant ADHD medications produced larger effect sizes than nonstimulants, suggesting that amphetamine- and methylphenidate-based stimulants are more effective treatments for ADHD symptoms."

About the Study

The meta-analysis reviewed data from 29 randomized, double-blind, placebo-controlled treatment studies lasting for two or more weeks published after 1979. Subjects included 4,465 children with ADHD, aged 8 to 15 years. ADHD was defined using criteria from the Diagnostic and Statistical Manual of Mental Disorders®, Fourth Edition, a publication of the American Psychiatric Association.

The trials in this meta-analysis studied 15 medications using 17 different outcome measures of ADHD symptoms, including "hyperactive," "inattentive," "impulsive" or "oppositional behavior." The most commonly identified medications were amphetamine and methylphenidate compounds. Non-stimulant medications identified were atomoxetine, bupropion, modafinil and desipramine. The 29 trials were stratified based on the three classes of drug studied (i.e., long-acting stimulant vs. short-acting stimulant vs. non-stimulant).

The researchers compared study outcomes using effect sizes, a standard statistical measure commonly used in meta-analyses to determine the magnitude of a particular effect resulting from an intervention, such as a drug used on a population, irrespective of the population size. Effect sizes are generally categorized as small (d = 0.2), medium (d = 0.5) and large (d = 0.8). After adjusting for study design differences, the researchers calculated effect size based on Total ADHD scores.

Stimulant medications showed an effect size significantly larger than non-stimulant medications. Within the stimulant class of medications, mixed amphetamine salts/amphetamine formulations demonstrated larger effect size compared to methylphenidate formulations. Results from this study were also recently published in Medscape General Medicine.

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Shire Development Inc. supported the study.

About ADHD

Approximately 7.8 percent of all school-age children, or about 4.9 million U.S. children aged 4 to 17 years, have been diagnosed with ADHD at some point in their lives, according to the U.S. Centers for Disease Control and Prevention (CDC). ADHD is one of the most common psychiatric disorders in children and adolescents. ADHD is a neurobiological psychiatric disorder that manifests as a persistent pattern of inattention and/or hyperactivity-impulsivity that is more frequent and severe than is typically observed in individuals at a comparable level of development. To be properly diagnosed with ADHD, a child needs to demonstrate at least six of nine symptoms of inattention; at least six of nine symptoms of hyperactivity/impulsivity; the onset of such symptoms before age 7 years; that some impairment from the symptoms is present in two or more settings (e.g., at school and home); that the symptoms have been present for at least six months; and that there is clinically significant impairment in social, academic or occupational functioning.

Although there is no "cure" for ADHD, there are accepted treatments that specifically target its symptoms. The most common standard treatments include educational approaches, psychological or behavioral modification, and medication.

Tell your doctor about any heart conditions, including structural abnormalities, that you, your child, or a family member, may have. Inform your doctor immediately if you or your child develop symptoms that suggest heart problems, such as chest pain or fainting.

ADDERALL XR should not be taken by patients who have advanced disease of the blood vessels (arteriosclerosis); symptomatic heart disease; moderate to severe high blood pressure; overactive thyroid gland (hyperthyroidism); known allergy or unusual reactions to drugs called sympathomimetic amines (for example, pseudoephedrine); seizures; glaucoma; a history of problems with alcohol or drugs; agitated states; taken a monoamine oxidase inhibitor (MAOI) within the last 14 days.

Tell your doctor before using ADDERALL XR if you or your child are being treated for or have symptoms of depression (sadness, worthlessness, or hopelessness) or bipolar disorder; have abnormal thought or visions, hear abnormal sounds, or have been diagnosed with psychosis; have had seizures or abnormal EEGs; have or have had high blood pressure; exhibit aggressive behavior or hostility. Tell your doctor immediately if any of these conditions or symptoms develop while using ADDERALL XR.

Abuse of amphetamines may lead to dependence. Misuse of amphetamine may cause sudden death and serious cardiovascular adverse events. These events have also been reported rarely with amphetamine use.

ADDERALL XR was generally well tolerated in clinical studies. The most common side effects in studies included: children - decreased appetite, difficulty falling asleep, stomachache, and emotional lability; adolescents - loss of appetite, difficulty falling asleep, stomachache, and weight loss; adults - dry mouth, loss of appetite, difficulty falling asleep, headache, and weight loss. Aggression, new abnormal thoughts/behaviors, mania, growth suppression, worsening of motion or verbal tics and Tourette's syndrome have been associated with use of drugs of this type. Tell your doctor if you or your child have blurred vision while taking ADDERALL XR.

Shire plc

Shire's strategic goal is to become the leading specialty pharmaceutical company that focuses on meeting the needs of the specialist physician. Shire focuses its business on central nervous system, gastrointestinal, general products and human genetic therapies. The structure is sufficiently flexible to allow Shire to target new therapeutic areas to the extent opportunities arise through acquisitions. Shire believes that a carefully selected portfolio of products with a strategically aligned and relatively small-scale sales force will deliver strong results.

Shire's focused strategy is to develop and market products for specialty physicians. Shire's in-licensing, merger and acquisition efforts are focused on products in niche markets with strong intellectual property protection either in the US or Europe.

For further information on Shire, please visit the Company's website: www.shire.com.

Statements included herein that are not historical facts are forwarding-looking statements. Such forward-looking statements involve a number of risks and uncertainties and are subject to change at any time. In the event such risks or uncertainties materialize, Shire's results could be materially affected. The risks and uncertainties include, but are not limited to: risks associated with the inherent uncertainty of pharmaceutical research, product development, manufacturing and commercialization; the impact of competitive products, including, but not limited to, the impact of those on Shire's Attention Deficit and Hyperactivity Disorder (ADHD) franchise; patents, including but not limited to, legal challenges relating to Shire plc's ADHD franchise; government regulation and approval, including but not limited to the expected product approval dates of SPD503 (guanfacine extended release) (ADHD), SPD465, extended release triple-bead mixed amphetamine salts (ADHD), MESAVANCE (mesalamine) with MMX technology (SPD 476) (ulcerative colitis), ELAPRASE (idursulfase) (Hunter Syndrome) and NRP104 (lisdexamfetamine dimesylate) (ADHD), including its scheduling classification by the Drug Enforcement Administration in the United States; Shire's ability to secure new products for commercialization and/or development; and other risks and uncertainties detailed from time to time in Shire's and its predecessor registrant Shire Pharmaceuticals Group plc's filings with the Securities and Exchange Commission, particularly Shire plc's Annual Report on Form 10-K for the year ended December 31, 2005.

Last reviewed:
By John M. Grohol, Psy.D. on
21 Feb 2009
Published on PsychCentral.com. All rights reserved.